This is Randall Carter's webpage for PSYC 355, Language and Thought.

Natural gesticulation, such as commonly accompanies any lively talk, is a language of its own, more widespread even, than the language of words—as far, I mean, as it is independent of words and alike in all nations
    --Arthur Schopenhauer, 1903

The field of psychology has learned a lot about gesture in the last century.

By browsing this site, you can figure out for yourself how this quote is inaccurate, although it's an impressive claim for its time.